1. Field of the Invention
The present invention relates to a meter for a motor vehicle of a type having a front cover which is provided in front of a meter case for protecting an interior of the meter.
2. Description of the Related Art
Heretofore, there has been such a meter for a motor vehicle which is installed on an instrument panel with its display face opposed to a driver's seat. The meter for the vehicle of this type has been hoodless in view of a space for installation, and has been generally provided with a front cover for protecting the interior (See Japanese Utility Model Registration No. 2602760, for example)
FIG. 4 is a schematic sectional view of the above described conventional meter for the vehicle which is installed on the instrument panel.
In FIG. 4, a meter 3 for a vehicle is arranged on an instrument panel 1 underneath a wind shield 2, and includes a meter case 4 having substantially C-shape in cross section, in which there are incorporated a dial plate 5, an indicator 8, and a movement 6 for actuating the indicator 8. A prism 9 composed of a prism formed of resin, glass or the like is fitted to an open face of the meter case 4 as a front cover. An apex of the prism 9 is directed upward.
A back face 9a of the prism 9 which is faced with the dial plate 5 of the meter 3 is inclined from a vertex P embracing a vertical angle θ so as to approach a lower end of the dial plate 5, while a front face 9b of the prism 9 is substantially in parallel to a front face of the dial plate 5. Other faces of the prism 9 than the front face 9b and the back face 9a, that is, a bottom face 9c and side faces 9d are painted in dark color.
The meter for the motor vehicle constructed as described above has been advantageous in that it has less surface reflection of daylight, and can be free from reflection on a window at night, as disclosed, for example, in Japanese Utility Model Registration No. 2602760.
The prism 9 to be employed as the front cover may be in various shapes, for example, triangular in section as shown in FIG. 5A, triangular only in its middle part while in a shape of a flat plate in its upper and lower parts as shown in FIG. 5B, in a shape of a convex lens having magnification with its end portion cut away as shown in FIG. 5C, and so on.
However, in case where the prism 9 having such a shape as indicated in FIG. 5C, there has been a problem that when the dial plate 5 in a shape of a perfect circle is seen through the prism 9 as shown in FIG. 6, the dial plate 5 in a shape of a perfect circle (shown by a dotted line) is vertically expanded due to the magnification inherent in the prism 9, and looks deformed as a virtual image 5A in a shape of a vertically elongated ellipse (shown by a solid line) as shown in FIG. 7. Therefore, the driver may have uneasy feeling.
In view of the above described problem of the prior art, an object of the present invention is to provide a meter for a motor vehicle in which uneasy feeling due to distortion of a virtual image of a dial plate can be eliminated.